A new survey of adult English language literacy finds that significant numbers of Americans face obstacles to their economic and social advancement because of reading difficulties. The U.S. Department of Education's National Assessment of Adult Literacy is the first survey of its kind since a study conducted in 1992, and the results are generating both attention and concern.

Thirteen percent of all people tested in the latest U.S. adult literacy survey are unable to do much more than sign a form, or read simple directions on a medical prescription. That means 30 million adults in the United States have what is called "below basic" literacy skills. Four million could not be tested because of language barriers.

The statistics have important implications for employment and earning power in the United States.

In announcing the new literacy statistics, Mark Schneider, commissioner of the National Center for Education Statistics, noted that only 35% of Americans with below basic literacy skills have full time jobs. Almost two thirds of Americans with proficient literacy skills are employed full time.

There are also striking differences in wages. "The median weekly earnings of the below basic population is $432 per week," Mr. Schneider noted, "far less than half the median of the population with proficient skills. The takeaway point? is that literacy pays."

The National Center for Education Statistics found that on average, the ability to read prose materials like magazines and newspapers has not changed in the United States over the past decade, while the ability to understand tax forms, checking statements and other quantitative materials has increased.

In assessing the 30 million Americans with below basic literacy skills, Department of Education officials stressed that changing immigration patterns in the United States should be taken into account.

"The period from 1992 through 2003 and early 2004 witnessed a very large increase in immigration, especially of Spanish speakers," noted Grover Whitehurst, who oversees the agency that administered the assessment. "And that corresponded with a change in language background. In 2003, compared to 1992, there was a lower proportion of adults who spoke English before starting school."

The National Assessment of Adult Literacy was conducted using sample surveys with more than 19,000 Americans aged 16 or older. The assessment found that Asian Pacific and African Americans made gains since the last survey, while the literacy skills of Hispanics declined.

Mark Schneider explains that could be a result of recent immigration trends. "There's been an increase in the number of Hispanic adults who are not native English speakers as well as an increase in the numbers of Hispanics who were not born in the United States, or who came here as teenagers or adults," he says.

The latest assessment found that literacy levels overall increased with schooling. But it also revealed a decline in the high-level literacy skills of college graduates. Only 31% could interpret long, complex texts, compared with 40% in the 1992 study.

Grover Whitehurst said that finding raises questions about the kind of education today's students are getting. "One of the issues that faces higher education as it becomes democratized and more and more students are attending college is, what are the results of that education," he noted. "Are people getting a paper diploma? What stands behind that diploma and what have people actually learned?"

The survey produced good news for older Americans. Those aged 65 and above scored higher than in the last survey. Women are also making gains, closing the gap with men in some literacy categories, and surpassing them in others.

Still, Dale Lipschultz describes the assessment as "a stark snapshot of America's ability to prosper in the 21st century." She is President of the National Coalition for Literacy, and the Literacy Officer for the American Library Association.

"When this many adults have low literacy skills," says Ms. Lipschultz, "it really compromises our ability to compete and enter a global economy,"

Dale Lipschultz believes that perhaps the best news to come out of the report is that America now knows the challenges it faces. She says the National Coalition for Literacy is focused on securing adequate funding for literacy programs. But she also believes reading skills can be raised only through a combined effort.

"We really need to engage in solution-based dialogue, working across party lines at every level of government and including the private and public sector as well," she says. "No one organization, institution or agency can solve this. And that's where our strength will be, if we are able to build strong partnerships."

Those partnerships can range from government agencies to individual families. After announcing the findings, Grover Whitehurst of the Department of Education said he planned to go home and tell his teenager he had found another reason to turn off the computer games and go read a book.